Object Element

1.The object element enables you to embed and configure the Silverlight plug-in in your HTML in a way that is compatible with all supported browsers.

2.An alternative to using the object element is to use the JavaScript embedding functions provided by the Silverlight.js helper file.

3.
The width and height attributes are required for cross-browser compatibility.

The type attribute and the specific value shown are also required. This value uses the Silverlight MIME type to identify the plug-in and the required version.

The indicated MIME type is used with Silverlight version 2 and all later versions

The data attribute and its value are recommended to avoid performance issues on some browsers.
 the trailing comma in the data value. This indicates a second data parameter that has an empty value.

The param element named source is required, and indicates the location and name of your application file.

Please check below links for more information.

http://msdn.microsoft.com/en-us/library/cc189089(v=vs.95).aspx

http://msdn.microsoft.com/en-us/library/cc838268(v=vs.95).aspx

Hope this will help you.

Thanks.